Corning Incorporated

Other

Schott Ag

Michael A Pell

Alexandre M Mayolet

Michele M L Meyer-Fredholm

Charlene Marie Smith

Alexandre Michel Mayolet

Robert W Sparrow

Paul Michael Then

Nikolay Timofeyevich Timofeev

The present invention is directed to a method of making large diameter metal fluoride sungle crystals that can be used in optical lithograpby systems, for example, excimer laser that operate below 200 nm. In addition, the invention is directed to metal fluoride single crystals suitable for use in such lithographic ststems, such fluoride crystals having a internal transmission of &#x2267;99.9% at 193 nm and &#x2267;99.0% at 157 nm.

Preparation of 157nm transmitting barium fluoride crystals with permeable graphite

The method of making a high quality fluoride crystalline optical microlithography lens element blank includes crystallizing a fluoride crystalline member with dimension &#x2267;200 mm from a melt, annealing the fluoride crystalline member and qualifying the resulting member for use as an optical microlithography lens element blank The fluoride crystalline optical lithography lens element blanks have multiple adjoining abutting crystalline subgrains with low boundary angles. The crystalline members made by the method are qualified for use as lens element blanks by a testing method including measuring their absorption spectra at 200 to 220 nm to determine absorbance at 205 nm and/or by making measurements of radiation diffracted by them.

Method of making a fluoride crystalline optical lithography lens element blank

This invention provides a method of detecting sub-ppm lead impurity levels in a below 200 nm transmitting optical calcium flouride crystal. The method includes providing a below 200 nm wavelength transmitting optical flouride crystal having a crystal light transmission path length, providing a 200-210 nm spectrophotometer having a light source for producing a transmission test wavelength in the range 200 to 210 nm and a transmission detector for measuring transmission of the test wavelength, and transmitting the transmission test wavelength in the range of 200 to 210 nm through the below 200 nm wavelength transmitting optical flouride light transmission path length and measuring the transmission of the 200 to 210 nm test wavelength through the path length to provide a lead ppb impurity level measurement less than 500 ppb. The invention provides for improved manufacturing of below 200 nm wavelength optical elements and optical fluoride crystals such as ultralow lead contaminated calcium flouride.

UV optical fluoride crystal elements for &#x3bb; &#x3c; 200nm laser lithography and methods therefor

The object of the present invention is a process of preparing an optical fluoride crystal containing barium fluoride, which comprises: loading a crucible with a barium fluoride starting material crystal feedstock which contains at least one oxide as impurity, and an effective and non-excess amount of at least one fluorinating agent which is solid at ambient temperature, melting said mixture within said crucible, growing the crystal, by controlled cooling of the molten mixture, controlled cooling of said crystal to ambient temperature, recovering said crystal; and which is characterized in that the oxide(s) resulting from the reaction between said fluorinating agent(s) and said oxide(s), the impurity or impurities, can be discharged from said crucible, in view of the intrinsic permeability of the material constituting it. Said process is particularly adapted for preparing 157 nm transmitting lithography excimer laser optical fluoride crystals in graphite crucibles.

The invention provides a &gE;4 kHz repetition rate argon fluoride excimer laser system for producing an UV wavelength 193 nm output. The &gE;4 kHz repetition rate argon fluoride excimer laser system includes an argon fluoride excimer laser chamber for producing a 193 nm discharge at a pulse repetition rate &gE;4 kHz. The &gE;4 kHz repetition rate argon fluoride excimer laser chamber includes magnesium fluoride crystal optic windows for outputting the 193 nm discharge as a &gE;4 kHz repetition rate excimer laser 193 nm output with the magnesium fluoride crystal optic windows having a 255 nm induced absorption less than 0.08 Abs/42 mm when exposed to 5 million pulses of 193 nm light a fluence &gE;40 mj/cm /pulse and a 42 mm crystal 120 nm transmission of at least 30%.

High repetition rate excimer laser system

Method of making <200 nm wavelength fluoride crystal lithography/laser optical elements

The present invention is directed to polycrystalline alkali metal or alkaline earth metal beads, in particular CaF beads, having a diameter greater than or equal to 100 &mgr;m, advantageously between 100 &mgr;m and 2 cm, and an apparent density greater than 60%, advantageously at least 90%, of the theoretical density of said fluoride. The invention is also directed to a process for the preparation of the foregoing alkali metal and alkaline earth fluoride beads, and for the preparation of single crystals of said fluorides using the foregoing polycrystalline beads.

Beads of a polycrystalline alkali-metal or alkaline-earth metal fluoride, their preparation, and their use for preparing optical single crystals

Method of making a high quality identifiable fluoride crystalline optical microlithography lens element blank for formation into an lens element of a microlithography system. The highly qualified fluoride crystalline characteristics of the fluoride optical lithography lens blank ensure its beneficial performance in the demanding microlithography manufacturing regime which utilizes high energy short wavelength ultraviolet laser sources. The fluoride crystalline optical lithography lens element blanks are comprised of multiple adjoining abutting crystalline subgrains with low boundary angles.

A polycrystalline alkali-metal or alkaline-earth metal (more particularly CaF2) fluorides, produced in an original form, namely in the form of beads; said beads having a diameter or equivalent diameter greater than or equal to 100 um, advantageously between 100 um and 2 cm and an apparent density greater than or equal to 60%, advantageously at least 90% of the theoretical density of said fluoride. A process for the preparation of single crystals of the corresponding alkali-metal or alkaline-earth metal fluorides that uses polycrystalline fluorides in the aforementioned original form.

Beads of polycrystalline alkali-metal or alkaline-earth metal fluoride, their preparation, and their use for preparing optical single crystals

The invention provides a high quality identifiable fluoride crystalline optical microlithography lens element blank for formation into an lens element of a microlithography system. The highly qualified fluoride crystalline characteristics of the fluoride optical lithography lens blank ensure its beneficial performance in the demanding microlithography manufacturing regime which utilizes high energy short wavelength ultraviolet laser sources. The fluoride crystalline optical lithography lens element blanks are comprised of multiple adjoining abutting crystalline subgrains with low boundary angles.

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Fountainebleau, France

Michael A Pell